From HD YouTube Downloader:
Free YouTube to Mp3 Downloader downloads all your favorite music from YouTube straight to you computer in a wide variety of formats. Free YouTube to Mp3 Downloader is also very easy to use.
Simply copy and past the YouTube URL into the YouTube to Mp3 Software and have your favorite song downloaded in seconds. YouTube to Mp3 Downloader also includes the ability to download YouTube Playlists, as well as multi-threading for downloading multiple songs or playlists at one time. Free YouTube to Mp3 Downloader software includes a wide variety of Audio Quality and Format Options. Download YouTube in more than just Mp3 including: M4A, ACC, WAV, OGG, FLAC, ALAC. Download YouTube in multiple quality levels including: Standard, Audio Book, Stereo 320kbit. For those who need even more options and variety YouTube to Mp3 Downloader is highly configurable. There are General, Advanced, Output and Tag options.